It has heretofore been proposed that exercise or jogging apparatus be provided which permits the person exercising to run in place. Generally such apparatus has comprised a frame and a mat or other resilient surface mounted directly to the frame or mounted on the frame by elastic cords or tension springs, much in the manner of trampolines. It has also heretofore been suggested that a jogging surface can be provided by a solid elastomeric body. Both types of such apparatus are typified in U.S. Pat. Nos. 3,004,623, 3,892,403, 4,037,834, 3,634,895 and 3,641,601.
Among the objectives of the present invention are to provide an approved jogging apparatus which includes a tightly tensioned mat that has a larger usable area within the frame, more uniformly distributes the load to the frame, is lower in cost, can have controlled energy absorption by the proper selection of materials, is safer in that it does not utilize open spaces between the mat and the frame, has a sturdy, safe supporting structure and is foldable for shipment and storage.
In accordance with the invention, the jogging apparatus includes a frame having an elastomeric body bonded thereto and the mat bonded to the body such that the elastomeric body is under shear and holds the mat tightly stretched in biaxial tension. The jogging apparatus further includes legs that are pivoted to the frame and are normally extended outwardly and downwardly but can be folded inwardly within the confines of the frame. The legs are mounted by a construction which tends to urge the legs yieldingly outwardly when they are extended and tends to urge the legs yieldingly inwardly when they are folded inwardly.